1. Technical Field
The invention relates to vehicle control and more particularly to control systems enabling both remote and vehicle mounted control of vehicle accessories and subsidiary systems such as aerial lifts, dump bodies, refuse compactors and concrete mixers.
2. Description of the Problem
Vehicle chassis are often called on to support operation of auxiliary systems such as aerial lifts, dump bodies, snowplows, wreckers, fluid delivery pumps, aircraft deicing equipment, refuse compactors and cement mixers. Typically these auxiliary systems require controls for operator input. In some cases the controls are simply switches or valves. Use of the controls can require the operator remain at a fixed location relative to or in the vehicle. While various remote systems allowing for operator mobility have been proposed, e.g. infrared, tethered, etc., radio has proved the most popular. An example of a system proposed for the radio remote control of a group of related systems either from controls installed on the vehicle or through a remote control device is Link, U.S. Pat. No. 5,975,162. Link proposed a system for a volatile liquid delivery vehicle which enabled remote control of power take off (PTO) for the liquid pump, of valves for control of delivery of the liquid, for transmission clutch control and for emergency shut down of the system.
Also well known are remote control devices for vehicle central locking systems and other specialized functions. Twelmeier et al., in German Patent Application DE 197 20 123 A1, recognized a tendency toward increasing multiplication of components as more and more onboard systems were provided with a remote controller, a receiver and on board control arrangements. Twelmeier et al. proposed a vehicle mounted system having a single receiver for receiving, demodulating, decoding and routing instructions from a plurality of different remote controllers to specific controllers for vehicle systems, e.g. to controllers for a central door locking control system and an for electric seat heating system.
Late 20th and early 21st century developments in motor vehicle control have moved toward placing major vehicle systems (e.g. engine, transmission, brakes) under a system controller and linking the system controllers to one another with a controller area network (CAN). The Society of Automotive Engineers (SAE) has published the J1939 standard which defines performance standards for controller area networks to be installed on motor vehicles and a protocol assuring smooth communication between controllers for major systems. The possibility of using a CAN for communication involving specialized systems using private or ad hoc signals is also provided for. The assignee of the present invention has developed vehicles incorporating two CANs, one linking the major controllers and a second, private CAN linking specialized devices which are not always, or even frequently, found across all vehicles of a class. For example, controllers for a power take off system for a utility vehicle may communicate using the private bus. Increased power demands by the power take off system may be coupled to the engine controller on the public bus through a electronic system controller (ESC)/body computer. Communication between the busses is effected by translation routines programmed into the ESC.
Unlicensed radio communication in the ISM (Industrial Scientific Medical) band set aside by the Federal Communications Commission has provided for considerable opportunity for new uses of radio below the maximum power outputs allowed by the FCC. The 2.4 MHZ to 2.5 MHZ band has proven particularly interesting. Commercial venders now provide a variety of equipment enabling two way communication using a wide variety of modulation schemes and frequency skipping techniques to improve bandwidth. Remote control applications of senders and receivers using the ISM bands and providing substantial bandwidth are increasingly popular.
It has been recognized that many of the auxiliary systems installed on vehicles, particularly commercial vehicles, are advantageously controlled remotely, or from both within or on the vehicle and remotely. Mechanical simplification of such systems promises greater flexibility in application and reduced hardware costs.